Safety device for liquid-fuel burners



W. K. BASSFORD.

SAFETY DEVICE FOR LIQUID FUEL BURNERS.

APPL ICAHON FILED MAY I, 1920.

Patented Feb. 8, 1921.

INENTOR ATTORNEYS.

UNITED STATES PATENT OFFICE.

WILLIAM K. BASSFORD, 0F METUCHE-N, NEEH JERSEY, ASSIGNOR OF ONE-HALF Tb JOHN L. MACDOWALL, OF PERTH AllIBOY, NEJT JERSEY.

SAFETY DEVICE FGB LIQUID-FUEL BURNERS.

Specification of Letters latent.

Patented Feb. 8, 1921.

Application filed May 1, 1920. Serial No. 378,111.

T 0 all 10 hum 2'2? may concern Be it known that I, lVILLIAM l'l. BASSFORD, a citizen of the United States, and a resident of Met-uchen, in the county of lliiddlcsex and State of New Jersey, have invented new and useful Improvements in Safety Devices for Liquid-Fuel Burners, of which the following is a specification.

This invention relates in general to safety devices for liquid fuel burners, and more particularly to a device of this character which will immediately extinguish the flame of the burner when the same becomes overheated or reaches a predetermined temperature, so as to prevent the liquid fuel in the reservoir from catching fire or exploding.

The objects of the invention are to provide a safety device of the character described embodying novel features of con struction whereby the flame of the burner will be automatically extinguished by thermostatically controlled mechanism when the burner becomes overheated or reaches a pre determined temperature; to provide such a device which can be easily and quickly applied to any conventional type of liquid :tuel burner without modification or alteration thereof; to provide a flu e extinguishing element normally held in inoperative position by a thermostatic element, the said thermostatic element being actuated by an abnormal rise in temperature of the burner to re lease the extinguishingelement which is then automatically and positively actuated into an extinguishing position to put out the flame; to obtain such a device which is simple and inexpensive in construction, and to obtain other results and advantages as may be brought out by the following description.

Referring to the accompanying d "awings, in which like numerals of reference indicate the same parts throughout the several views.

Figure 1 is a vertical sectional view through a conventional type of liquid fuel burner, showing a sai'ety device constructed in accordance with my invention applied thereto, the safety device being shown in side elevation;

Fig. 2 is a transverse vertical sectional view taken on the line 2-2 of Fi 1;

Fig. 3 is horizontal sectional view taken on the line 3-3 of Fig. 1 the safety device being shown in plan view;

Fig. 4 is a view similarto Fig. 3 showing a modified form oi thermostatic element. and I Fig. 5 is an enlarged sectional view through the thermostatic element taken on the line 55 oi? l.

in the specific embodiment of the invention illustrated in Figs. 1-3 inclusive, the numeral 1 designates a liquid fuel reservoir which is provided with a central vertically disposed air tube 2 which carries at its upper end an air distributor 3. An annular wick tube 4 surrounds the said air tube 2 at its upper end and is spaced therefrom, the said wick tube being removably supported in a conventional manner upon the upper end of the liquid fuel reservoir 1, and an annular wick 5 being mounted between the said air tube and the wick tube. A. burner screen 6 is mounted upon the upper end of the liquid fuel reservoir 1, and surrounds the wick tube el, the said screen being provided at the top thereof with an opening 7 through which the wick tube projects. The above described construction is all conventional, and no claim to novelty is made thereon.

My improved safety device includes an extinguishing sleeve 8 which loosely sur rounds the wick tube l and is slidable vertically thereon, "the said sleeve when in its normal position being disposed slightly below the upper edge or the wick tube 1-. A helical spring 9 surrounds the wick tube 4: and is interposed between the base of the same and outwardly projecting lugs 10 on the lower end of the extinguishing sleeve 8, the said. spring normally tending to force the extinguishing: sleeve 8 vertically upward above the top the wicl: tube l and into engagement with a cap ring ll which is ad justably and detachably connected to the air distributor 3. This cap ring 11 is pre1terably formed in two substantially semi-cir cular sections which are .detacha-bly connected by means or" bolts 12 passing through upturned lugsl on the ends of the respective sections of the ring. ll hen the extinguishing sleeve 8 is forced into engagement with the cap ring 11 as shown in dotted lines on Fig. 2, a substantially air-ti ht chamber is formed around the frame oi the burner, so that insuiiicient air is admitted to the flame to support combustion and the flame is accordingly quickly extinguished.

For the purpose of maintaining the ex tinguishing sleeve 8 in normal inoperative position, a thermostatic member id is utilized, the said thermostatic element comprising substantially semi-circular strip oi steel 15 to which is riveted as at 16 on the inner side thereof a similarly shaped strip of copper 17, the ends of said strips carrying radially inwardly projecting pins 18 which engage diametrically opposite openings 19 in the extinguishing sleeve 8. This element is rigidly secured at a suitable position on the inner side of the burner screen 6 in any suitable manner as by means of the bolts 20. Normally the pins 18 engage the openings 15) in the extinguishing sleeve 8 and project through the same, but when the burner reaches a predetermined temperature, for instance 370-4t00 F, or becomes overheated, the copper strip 1"? of the thermo static member 14 having a higher coeiiicient oi expansion than the steel strip 15, the said thermostatic element will expand and tend to straighten thereby withdrawing the pins 18 from the openings 19, as indicated by dotted lines on Fig. 3. As soon as the pins are thus released from the openings 19, the spring 9 forces the extinguishing sleeve 8 into snug engagement with the cap ring 11, and holds the same there so as to extinguish the flame. To reset the safety device the thermostatic element is allowed to cool, and the extinguishing sleeve 8 then forced downward against the action of the spring 9 to allow the pins 18 to again engage the openings 19 in the sleeve 8.

A modified form of thermostatic member is shown by Figs. 1 and 5, the said member 20 being in the nature of a Bourdon tube. In the present instance this Bourdon tube comprises two arcuate sections 21 which are connected at their inner ends by a T-conneo tion 22, so that the member 20 is substantially semi-circular in shape. The T connection 22 is provided with a nipple 23 which projects through an opening in the burner screen 5 and has threaded thereon clamping nut 24, whereby the thermostatic member 20 is rigidly secured to the screen in a position substantially the same as that of the thermostatic member 1 1 above described. The ends of the sections 21 of the thermostatic member 20 are provided with caps 24 which are formed with inwardly and radially projecting pins or studs 25 adapted to engage the openings 19 in the extinguishing ring 8 in the same manner as do the pins 18. The Bourdon tube is filled with any suitable fluid which will vaporize at a predetermined temperature, so as to expand the tube and cause the pins 25 to be removed from the openings 19, the operation of the tube being similar to the conventional Bourdon tube in a steam pressure gage. I have found water to be satisfactory for this purpose, but can also use a combination of glycerin and alcohol or a lubricating oil with a low flash point, and I do not desire to be limited to any par ticular fluid. The thermostatic tube 20 may be filled with the fluid through the nipple 23, and a closure plug 26 n'rzy be titted into the end of the nipple for closing the tube, as shown by Fig. 5. With this construction, when the burner reaches a predetermined temperature or becomes overheated, the fluid in the thermostatic tube 20 will vaporize and expand so as to cause the tube sections 21 to spread and thereby withdraw the pins or studs 25 from the openings 19 in the extinguishing sleeve 8. Thereupon the operation of the extinguishing sleeve by the spring 9 is identical with that above described in connection with Figs. 13 inclusive.

It will be seen that a safety device constructed in accordance with my invention can be easily and quickly applied to any conventional type of burner without modification or alterations of the burner, the operation and construction of the said safety device being independent of the burner to which it is attached. The cap ring 11 may be vertically adjusted upon the air distribut ter 3, and can be applied to air distributers of difiierent diameters through the detachable connection of the sections of the ring by means of the bolts 12. While I have shown and described two possible embodiments of my invention, many modifications and changes can be made in the construction of the invention by those skilled in the art without departing from the spirit and scope thereof, and I do not desire to be limited in the use of my invention except as required by the following claims when construed in the light of the prior art.

Having thus described the invention what I claim is:

1. In a device of the character described, the combination with a burner, of an extinguishing member having a recess therein, and a thermostatic element having a projection thereon to engage said recess to normally hold said extinguishing member in an inoperative position, said projection on the thermostatic element being disengaged from said recess when the burner reaches a predetermined temperature.

2. In a device of the character described, the combination with a burner, of an extinguishing member, and a curved thermosstatic element secured to the burner and nor mally engaging said extinguishing member to hold the same in an inoperative position, said thermostatic element expanding and tending to straighten so as to disengage it self from said extinguishing member when the burner becomes overheated.

3. In a device of the character described, the combination with a burner, of an extinguishing member having a recess therein, and a curved thermostatic element secured to said burner and having a projection thereon uori'nally engaging said recess to hold the extinguishing member in inoperative position, said thermostatic element expanding and tending to straighten so as to disengage said projection from said recess When the burner reaches a predetermined temperature.

4. In a device oi the character described, the combination with a burner, of an eX- tinguishing member having a pair of 0ppositely disposed recesses therein, and a substantially e -shaped thermostatic element secured to the burner and having a projection upon each arm thereof to normally engage the respective recesses in said extinguishing member to hold the same in an inoperative position, the said arms of the thermostatic element spreading apart when the burner becomes overheated and Withdrawing said projections from the said recesses.

5. In a device of the character described, the combination With a burner, of an extinguishing member normally disposed upon one side of the flame oil? the burner, a cap mounted on said burner on the side of the flame opposite the said extinguishing member, thermostatic means for normally holding said extinguishing member in inoperative position, said thermostatic means releasing said extinguishing member when the burner reaches a predetermined temperature, and means for actuating said extinguishing member into engagement with said cap to form a substantially air-tight chamber around the flame When the said extinguishing member is released by said thermostatic holding means.

WILLIAM K. BASSFOBD. 

